Commit 68d3b27e authored by Mark Harmstone's avatar Mark Harmstone Committed by David Sterba
Browse files

btrfs: move priv off stack in btrfs_encoded_read_regular_fill_pages() 



Change btrfs_encoded_read_regular_fill_pages() so that the priv struct
is allocated rather than stored on the stack, in preparation for adding
an asynchronous mode to the function.

Signed-off-by: default avatarMark Harmstone <maharmstone@fb.com>
Reviewed-by: default avatarDavid Sterba <dsterba@suse.com>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent 973a4326

fs/btrfs/inode.c

+18 −11
Original line number Diff line number Diff line
@@ -9085,16 +9085,21 @@ int btrfs_encoded_read_regular_fill_pages(struct btrfs_inode *inode, 
					  struct page **pages)

{

	struct btrfs_fs_info *fs_info = inode->root->fs_info;

	struct btrfs_encoded_read_private priv = {

		.pending = ATOMIC_INIT(1),

	};

	struct btrfs_encoded_read_private *priv;

	unsigned long i = 0;

	struct btrfs_bio *bbio;

	int ret;



	init_waitqueue_head(&priv.wait);

	priv = kmalloc(sizeof(struct btrfs_encoded_read_private), GFP_NOFS);

	if (!priv)

		return -ENOMEM;



	init_waitqueue_head(&priv->wait);

	atomic_set(&priv->pending, 1);

	priv->status = 0;



	bbio = btrfs_bio_alloc(BIO_MAX_VECS, REQ_OP_READ, fs_info,

			       btrfs_encoded_read_endio, &priv);

			       btrfs_encoded_read_endio, priv);

	bbio->bio.bi_iter.bi_sector = disk_bytenr >> SECTOR_SHIFT;

	bbio->inode = inode;
@@ -9102,11 +9107,11 @@ int btrfs_encoded_read_regular_fill_pages(struct btrfs_inode *inode, 
		size_t bytes = min_t(u64, disk_io_size, PAGE_SIZE);



		if (bio_add_page(&bbio->bio, pages[i], bytes, 0) < bytes) {

			atomic_inc(&priv.pending);

			atomic_inc(&priv->pending);

			btrfs_submit_bbio(bbio, 0);



			bbio = btrfs_bio_alloc(BIO_MAX_VECS, REQ_OP_READ, fs_info,

					       btrfs_encoded_read_endio, &priv);

					       btrfs_encoded_read_endio, priv);

			bbio->bio.bi_iter.bi_sector = disk_bytenr >> SECTOR_SHIFT;

			bbio->inode = inode;

			continue;
@@ -9117,13 +9122,15 @@ int btrfs_encoded_read_regular_fill_pages(struct btrfs_inode *inode, 
		disk_io_size -= bytes;

	} while (disk_io_size);



	atomic_inc(&priv.pending);

	atomic_inc(&priv->pending);

	btrfs_submit_bbio(bbio, 0);



	if (atomic_dec_return(&priv.pending))

		io_wait_event(priv.wait, !atomic_read(&priv.pending));

	if (atomic_dec_return(&priv->pending))

		io_wait_event(priv->wait, !atomic_read(&priv->pending));

	/* See btrfs_encoded_read_endio() for ordering. */

	return blk_status_to_errno(READ_ONCE(priv.status));

	ret = blk_status_to_errno(READ_ONCE(priv->status));

	kfree(priv);

	return ret;

}



ssize_t btrfs_encoded_read_regular(struct kiocb *iocb, struct iov_iter *iter,